There are various types of recording mediums for recording digital data such as music contents and video data, including magnetic disks, optical disks, magneto-optical disks, etc. A semiconductor memory card as a kind of the recording mediums uses a semiconductor memory such as a flash ROM as a recording device. For miniaturization of the recording medium is progressing, the semiconductor memory card has rapidly widespread especially in compact portable equipment such as digital still cameras and mobile phone terminals.
An example of the semiconductor memory card is a semiconductor memory card having a copyright protection function so as to store digital copyrighted works therein (refer to Patent document 1, for example). To protect copyright of digital works, this semiconductor memory card is characterized by having an authentication area where an external device is permitted to access only when authentication of the external device succeeds and a non-authentication area where an external device is permitted to access, irrespective of the authentication result.
On the other hand, data stored in the semiconductor memory card is managed by a file system and the user can easily handle the stored data as a file. Conventionally used file systems include a FAT file system (for details, refer to Non-patent document 1). The FAT file system is a file system generally used in information equipment such as PC. The FAT file system centrally manages location of data constituting the file by using a table called as a FAT (File Allocation Table). When the data stored in the semiconductor memory card is managed by the FAT file system, devices capable of interpreting the FAT file system can access the data stored in the semiconductor memory card and thus data can be transmitted or received between the devices through the semiconductor memory card.
However, file systems include an UDF (Universal Disk Format) file system (for details, refer to Non-patent document 2) and NTFS file system (New Technology File System) in addition to the FAT file system. When file systems which the devices can interpret are different from each other, the devices cannot transmit or receive data to or from each other through the semiconductor memory card.
Conventionally, as a method of solving the above-mentioned problem, a method of providing an area for storing a plurality of pieces of file system management information and area for storing common file data in information recording medium has been proposed (refer to Patent document 2, for example). According to the conventional method, after the information recording medium is inserted into the device, a file system to be used is selected and setting a starting address of the area in which the corresponding file system management information is stored as an address 0, the file system management information is accessed. By selecting one of the plurality of pieces of the file system management information in this manner and using it, data can be transmitted or received between different devices that interpret different file systems through the common information recording medium.
Patent document 1: Japanese Unexamined Patent Publication 2003-233795
Patent document 2: Japanese Unexamined Patent Publication Hei8-272541
Non-patent document 1: ISO/IEC9293, “Information Technology-Volume and File Structure of Disk Cartridges for Information”, 1994
Non-patent document 2: OSTA “Universal Disk Format Specification Revision 1.50”, 1997